hdbiker1

My first Mega had a wiped out throat. Took it to Jason in person because it seemed he didn't believe me. At that time we got into a discussion about he couldn't believe how I got a barrel that was so screwed because of all the QC inspections they go through. Mega was very good about replacing it. They contract Bergara to make these barrels. They are very nice looking and will shoot sub moa.

Yes, chambers not concentric with the bore. I went through three barrels, each were non-concentric. I was told it was because the reamer bushings they had were not compatible with polyganol rifling. The only good thing is their customer service was great and their shop is only about 35 miles away. The other thing I noticed, was their QC inspector didn't have a borescope or a loupe.

You might also mention the o.d. since they list three different sizes.

That load sounds pretty hot, unless you're using Winchester brass. In my rifle, 42.8gr of 4064 in LCLR brass and the 168 SMKs starts to leave ejector marks. So I'm going to use wither 41.8 or 42.7. Currently 41.8 shoots .8moa at 300yds, on average with about 5.0 moa come up from a 20".

I don't know if from the same lot, but I was given the option to find a different caliber barrel off their rack, but found similar chambers. Yes I do hear quite a few positive reviews. The shop inspector asked me what kind of shooting I do and told him mostly off the bench for groups. He said most that buy their barrels are blasters, but I don't buy that. I did notice that they don't have or use a borescope at all. At least it was never used the three times I was there at their shop in St Helens, Or. I'm thinking that if I ever try another one of their barrels, I'll just buy a blank (quoted about $80 when they become available sometime this summer possibly) and have my gunsmith chamber it.

I just had one shear off just like that. It had 1378 rnds on it. I already had a spare. I'd also noticed that the firing pin head is mushrooming. Don't know if it affects anything, but I will be getting another. Btw, this was on the 3rd rnd out of 5 in the mag.

I'd like to tell you guys about my experience with both Mega and BHW barrels. I bought a 20" Mega awhile back and got it home and did a thorough inspection, where I found the throat was totally fubar'd. Contacted Jason at Mega and he was kind of skeptical so I took it in for him to examine. The damage was plainly visible just by eye balling. He couldn't figure it out since he claimed all the inspections they go through. But to his credit, he happened to have one on hand and immediately replaced it. All was good. Next was a BHW .260 barrel that I couldn't get to shoot consistently. So I looked at the chamber real well and found it not concentric to the bore. Took it to my gunsmith and had him bore scope it and he determined it was nonconcentric to the bore. Took it to BHW and they replaced it immediately. Took it home and found the same thing and took it back. I was told at their shop that they were having troubles getting the correct reamer bushing for their rifling. Finally they had to build me a new barrel, but alas, the same thing, but not quite as bad. So to date I have a 24" .260 BHW barrel that I haven't shot and don't know what to do with it. I can tell you that the polyganol barrels do give out higher velocities. So I would suggest anyone that bought these or any barrel to check out the chamber and throat really well. Customer service from both companies was exemplary. Maybe I'm just one of those people that can't be pleased.

Better yet, I'd like to know if it affects accuracy at all, or are these kind of fixes just for a feel good thing.

My thoughts on barrel break in is to smooth out any machine marks left by the reamer in the throat. Lapping a barrel just smoothes out any burrs, ridges and any irregularities left during the rifling process. By using a lead lap formed in the rifling and coated with a fine abrasive, it is worked back and forth and using several laps. I'm told this is an acquired skill to know the correct feel. But you all knew that so what do I know. <dontknow> But my experience with custom barrels has been usually within 5 rnds, all copper has ceased. I did do the Mike Rock barrel treatment method once and didn't get any copper fouling until after about 100 rnds. Factory barrels are another story.

The measurements I refer to, basically show the headspace of the weapon the brass was fired from in a round about way.

Sounds like you might have more than one issue. I just don't know if it's related to the upper or lower. Trial and error comes to mind. Swap out uppers and lowers and see what happens. Good luck. I'm currently working on two uppers for a MaTen, one in 308 and the other in 260. Accuracy is not consistent. I'm hoping it's just a load thing.

The oal of the brass doesn't mean anything. You're just measuring the initial stretch from firing. What you need to do is measure from the datum point to the case head.

Can't make out the wear on the bolt. Is it on the sides of the lugs or the locking portion (where it mates with the barrel extension). I'd expect on both, but more uniform on the locking than the sides. Also, on the receiver extension, is the wear on the top or bottom? If the top, I suspect raising the rear of the upper had something to do with that. My thinking is maybe one of those tension take down pins would work better than bedding the receivers. But I really don't know for sure.

In your post #16, what brass are you using and how much 4064? I'll be curious how much the groups will be affected by going with 42.5gr of 4064.

I became curious with the .223/5.56 cases and found the info for capacities on line, but didn't find anything for the .308/7.62 cases. So I weighed, filled with water and found that for the most part, LC brass whether match, lr or m80 were the same at approx 54.8gr. Win brass had me stumped because I had some that the total weight with primer was 183 (100 or so case) and the rest 162. The capacities were 54.1 and 56.2 respectively. R-P cap. was 55.9. Lapua was 54.5. Fed was 54.6. I also did some other headstamps as well, but don't use them for any comparisons. Mind you, these are my numbers so you might get something different depending on how high you fill with water and such. I don't know of an exact formula for how much powder to use when your capacity changes by a certain percentage, but it has at least given me a guide on where to start and has been pretty close (usually within .5gr).